Art of flame treating glassware



June 16, 1936. CORY 2,044,566

ART OF FLAME TREATING GLASSWARE Filed Oct. 29, 1934 Patented June 16,1936 ART OF FLAME TREATING GLASSWARE Harvey Cory, Chicago, 111.

Application October 29, 1934, Serial No. 750,513

4 Claims. '(CI. 49-77) My invention is concerned with a flame treatmentdesigned particularly for glassware, for the purpose of fixing thereonstripes or other decorations which are applied to a surface thereof. Inthe past it has been customary, after application of striping or otherdecoration to the surface of glassware to fire simultaneously a largenumber of such articles in a leer. At an elevated temperature of perhaps1500 F., the glassware remains in the leer for several hours. As aresult of such an extended operation the striping or decoration becomesfixed permanently to the glass surface. Some such firing treatment asthis, which is expensive both in time and money, has commonly beenresorted to for the fixing of striping or other decoration uponglassware.

.According to my invention the striping (the term striping or stripe"including decorations generally, wherever used hereinafter) is firstapplied to the surface of glassware (the term glassware including china,porcelain, and other vitreous materials which lend themselves to thetreatment hereinafter described), and then is subjected to the action ofa flame. This opera-- tion is very briefperhaps not over two minutes.The operator in attendance is enabled to observe the eifect and therebydetermine the proper moment for termination of the treatment. This isimportant because there are many variables which determine the correcttemperature, mode and time of treatment, such as differences in theglass itself, lack of uniformity in the materials employed for thestriping, etc. Obviously such a treatment as my invention is concernedwith, requiring but a brief time for its application and economizinggreatly in the expense as well as improving the results, has manyadvantages.

As illustrative of an apparatus which is suitable for the carrying outof my process, I have presented in the accompanying drawing two figures,the first of which is a view in plan, and the second a vertical sectionon line 22 of Fig. 1.

The work to be treated. here shown as a glass tumbler W, may be restedupon a heat insulating pad 2 supported on the upper surface of aturntable T affixed to the upper end of a spindle 3 by which it isrotated. Immediately above the table and extending circumferentially, bypreference, in excess of 180 is a shield S lined on its interior withinsulation material i, such as asbestos. The shield is apertured atoneor more places for the insertion therethrough of burners B. It isdesirable that two or three of such burners be used, the latter numberbeing illustrated. These several burners are connected by a common pipe5 with a source of fuel supply, a. valve 6 being interposed at a pointwhich controls the flow of fuel to all of the burners. To supportcombustion, an air pipe I may connect each of the burners with a sourceof supply. A valve 8 is interposed in this pipe at a point whichcontrols the air flow to each of the burners.

In practice I have successfully used this invention for the flxing ofstriping with liquid platinum upon borisilicate glassware. A thinstriping of this character is indicated by x upon the work in Fig, 2.Liquid platinum comprises lavender oil which acts as a vehicle forevenly suspending the particles of platinum. When first applied, itpresents a dull pale color bearing little or no resemblance to platinum.The glassware is then rested upon the turntable which is set in motionand flames are then projected from the several burners upon theglassware. These flames strike at spaced circumferential intervals uponthe striping and because of the rotation of the glassware upon theturntable every portion of the striping is moved successively into thezone of flame treatment. The speed of rotation may beslow, perhaps 30 to60 R. P. M. Initially the flame temperature at the point of contact withthe glass is relatively low, but is quickly raised to a much higherpoint. Satisfactory results are obtained by the application of a flameof around 700 F. temperature when first applied, and which, after fiveor ten revolutions of the turntable, is then raised to a pointapproximating 1700 F. This flame treatment may continue for perhaps twominutes. The fuel used may be ordinary manufactured or natural gas, orliquid fuel which is suitable for the purpose. For supportingcombustion, air at a low pressure of perhaps one pound is sumcient.

As the operation proceeds the lavender oil becomes thoroughly dried, butwithout oxidizing. The color of the striping will gradually change untila rich platinum tone develops. At this point the treatment should stopand a skilled attendant can readily determine the correct time forterminating the treatment.

It is important that the glassware be subjected to a flame treatment insuch a manner as not to set up strains in its structure. The flameoperation above described may be safely applied because of the fact thata high temperature is maintained for a relatively short time, wherebythe glassware in its entirety is not appreciably heated.

It is manifest that the flame treatment of-my invention is applicable tothe fixing of striping where a non-oxidizing material other than liquidplatinum is used. For example, gold is one material which lends itselfto this treatment. While the invention is particularly advantageous forthe treatment of narrow stripes which occupy only a small area upon thesurface of glassware, it may also be used with wider stripes or heavydecoration, in which event-the temperature and time of treatment may bevaried to best meet requirements.

I claim:

. l. The method of firing decorations on articles made of bori-silicateglass, which comprises the step of applying a decorative coatingcomposition to a portion of the articles surface, and thereaftersubjecting that portion of the articles surface whereon the decorationis applied to the action of a flame while subjecting the remainder ofthe surface of the article to room temperature.

2. The method of firing decorations on articles made of bori-silicateglass, which comprises the step of applying a decorative coatingcomposition to a portion of the articles surface, and thereaftersubjecting that portion of the article's surface whereon the decorationis applied to the action of a flame whose temperature is initially andfor a brief period less than that which ob- *oration is applied to theaction of a flame whose temperature range is between 700 F. and 1700 F.,the minimum temperature obtaining at the commencement of the treatment,and simultaneously subjecting the remainder of the surface of thearticle to room temperature.

4. The method of firing decorations extending circumferentially onarticles made of bori-siiicate glass which comprises the step ofapplying a decorative coating composition to a circumferential portionof the article's surface, rotating the article before a flame whichsuccessively plays upon every portion of the article's surface whereonthe decoration is applied, and simultaneously subjecting the remainderof the surface of the article to room temperature.

HARVEY CORY.

